256 Notes on the Glaciation of the Pacific Coast. [March 
in the amount of precipitation. It would only be necessary to 
suppose a slight diminution of temperature to secure all the 
additional force required to extend the present glaciers of South- 
eastern Alaska, British Columbia, and of the Cascade Range in 
Washington Territory and Oregon, until they should occupy all 
the channels of the Alexander Archipelago, fill the space occu- 
pied by the Strait of Georgia between Vancouver’s Island and 
the main-land, and cover the whole valley between Mount Rainier 
and the Olympian Mountains, where now we find the vast moraine 
deposits of the islands and shores of Puget Sound. Southward, 
in Oregon, the Willamette valley is filled in a similar manner 
by an extension of the glaciers still lingering on the flanks of 
Mounts Hood and Shasta. The absence of drift on the southern 
shore of Vancouver’s Island seems to point to a termination of 
the northerly movement in the Strait of Juan de Fuca, where, 
perhaps, the confluent streams turned westward and sent off vast 
drift-laden icebergs to the sea. Mount Baker, immediately to 
the east of this point, is upwards of ten thousand feet high, and 
still preserves glaciers on its flanks, and would have aided greatly 
in this movement. 
In the boulders about Puget Sound, and in the striated surfaces 
which must exist somewhere in the vicinity, there is doubtless 
positive evidence of the direction of the ice movement which 
brought to its present position the immense ridges and piles of 
glacial débris forming the fertile soil of this remarkable region. 
It is to be hoped that local observers will not long leave the 
world in doubt as to the source of the boulders and the direction 
of the striz about Puget Sound. To me the shores and islands 
of that region had the appearance of being the terminal deposits 
of confluent glaciers coming down from the flanks of Rainier to 
the southeast, and from the lower portions of the Cascade Range 
farther north, joined by smaller glaciers from the Coast Range 
on the west. It is clear that the earlier glacial movements on 
the Pacific coast were local in character, and must be studied in- 
dependently of those east of the Rocky Mountains. The ancient 
glaciers of the Pacific coast can be understood only by reference 
to the glaciers which still linger at the head of all its numerous 
valleys, inlets, and fiords. In these the investigator has his 
vera causa ever before his eyes to guide his steps and to assist 
his imagination. 
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